U.S. patent application number 09/905802 was filed with the patent office on 2003-04-03 for multi-purpose absorbent and cut-resistant sheet materials.
This patent application is currently assigned to The Procter & Gamble Company. Invention is credited to Alonso, Mario, Gilfert, Charles John, Hamilton, Peter Worthington, Lake, Kirk Wallace, Lockett, Nicole Alise Renee, Poland, James Edward.
Application Number | 20030064194 09/905802 |
Document ID | / |
Family ID | 25421500 |
Filed Date | 2003-04-03 |
United States Patent
Application |
20030064194 |
Kind Code |
A1 |
Lake, Kirk Wallace ; et
al. |
April 3, 2003 |
Multi-purpose absorbent and cut-resistant sheet materials
Abstract
A multi-purpose sheet material comprising an absorbent material
and a bonding material in contact with the absorbent material. The
bonding material and the absorbent material are thermally bonded so
that the bonding material and the absorbent material form an
amalgamated layer therebetween. A fluid impermeable material is in
contact with the absorbent material. The bonding material has a
basis weight in the range of 4 g/m.sup.2 to about 100 g/m.sup.2
and, the sheet material exhibits a lamination efficiency of at
least 10 g/m.sup.2.
Inventors: |
Lake, Kirk Wallace;
(Cincinnatic, OH) ; Hamilton, Peter Worthington;
(Cincinnati, OH) ; Lockett, Nicole Alise Renee;
(Cincinnati, OH) ; Poland, James Edward; (Park
Hills, KY) ; Gilfert, Charles John; (Cincinnati,
OH) ; Alonso, Mario; (Loveland, OH) |
Correspondence
Address: |
THE PROCTER & GAMBLE COMPANY
INTELLECTUAL PROPERTY DIVISION
WINTON HILL TECHNICAL CENTER - BOX 161
6110 CENTER HILL AVENUE
CINCINNATI
OH
45224
US
|
Assignee: |
The Procter & Gamble
Company
|
Family ID: |
25421500 |
Appl. No.: |
09/905802 |
Filed: |
July 13, 2001 |
Current U.S.
Class: |
428/137 |
Current CPC
Class: |
Y10T 428/24322 20150115;
B32B 27/306 20130101; Y10T 428/24826 20150115; B32B 27/32 20130101;
Y10T 428/24273 20150115; B32B 2367/00 20130101; B32B 5/18 20130101;
B32B 27/36 20130101; B32B 2307/7265 20130101; B32B 2307/581
20130101; B32B 33/00 20130101; Y10T 442/155 20150401; B32B 7/02
20130101; B32B 2323/10 20130101; B32B 27/38 20130101; B32B 2327/06
20130101; B01J 20/28023 20130101; B32B 2323/043 20130101; A47J
47/005 20130101; B32B 7/12 20130101; B32B 27/40 20130101; B32B
27/10 20130101; B65D 81/264 20130101; B32B 2375/00 20130101; B01J
20/28033 20130101; B01J 20/28035 20130101; B32B 5/02 20130101; B32B
2323/046 20130101; B32B 2363/00 20130101; B32B 2307/584 20130101;
Y10S 428/911 20130101; Y10T 428/24331 20150115; B32B 19/046
20130101; B32B 3/266 20130101; B32B 27/304 20130101; B32B 2331/04
20130101; B32B 2317/122 20130101 |
Class at
Publication: |
428/137 |
International
Class: |
B32B 003/10 |
Claims
What is claimed is:
1. A cut-resistant and absorbent multi-purpose sheet comprising:
(a) an absorbent material having a top layer and a bottom surface;
(b) said top layer comprising an amalgamation of said absorbent
material and a continuous sheet of bonding material; (c) a fluid
impermeable material in contact with said bottom surface; wherein
said bonding material has a basis weight in the range of 4
g/m.sup.2 to about 100 g/m.sup.2; and, wherein said sheet material
exhibits a lamination efficiency of at least 10 g/m.sup.2.
2 The sheet material of claim 1, wherein said fluid impermeable
material comprises a sheet attached to said bottom surface.
3. The sheet material of claim 1, wherein said bonding material has
a laminated open area of at least 0.5 percent.
4. The sheet material of claim 1, wherein said bonding material
comprises a substantially non-absorbent material having holes.
5. The sheet material of claim 1 wherein said bonding material has
a basis weight of from about 15 g/m.sup.2 to about 50
g/m.sup.2.
6. The sheet material of claim 1, wherein said absorbent material
comprises a fibrous material.
7. The sheet material of claim 6, wherein said absorbent material
has a basis weight of from about 200 lb/3000 ft.sup.2 (0.325
kg/m.sup.2) to about 400 lb/3000 ft.sup.2 (0.651 kg/m.sup.2).
8. The sheet material of claim 7, wherein said absorbent material
has a basis weight of from about 220 lb/3000 ft.sup.2 (0.358
kg/m.sup.2) to about 280 lb/3000 ft.sup.2 (0.456 kg/m.sup.2).
9. The sheet material of claim 1, wherein said sheet material is
generally planar.
10. The sheet material of claim 1, wherein said absorbent material
and said bonding material are coextensive with said impermeable
material.
11. The sheet material of claim 1 further comprising at least one
series of weaknesses wherein said at least one series of weaknesses
is extensive through said bonding material and at least a portion
of said absorbent material.
12. A multi-purpose sheet material comprising: (a) an absorbent
material having opposing first and second surfaces; (b) an
impermeable material in contact with said first surface of said
absorbent material; (c) a bonding material in contact with said
second surface of said absorbent material and forming an
amalgamated layer therebetween; and, wherein said sheet material
exhibits an absorbent efficiency of at least 0.2, a lamination
efficiency of at least 10 g/m.sup.2, and a slice resistance of at
least 30 kgf/cm.
13. The sheet material of claim 12, wherein said bonding material
forms a continuous network.
14. The sheet material of claim 12, wherein said bonding material
comprises a synthetic material.
15. An absorbent, cut-resistant, and shred-resistant article,
comprising: a sheet material, wherein the sheet material exhibits a
cut-resistance of at least 30 kgf/cm, an absorbent efficiency of at
least 0.2, and a lamination effiency of at least 10 g/m.sup.2.
16. The article as recited in claim 15, wherein said sheet material
comprises an absorbent material having a first surface and a second
surface, a bonding material joined to said first surface of said
absorbent material and forming an amalgamated layer therebetween,
and an impermeable material joined to said second surface of said
absorbent material.
17. The article as recited in claim 16, wherein said bonding
material comprises a substantially non-absorbent material having
holes.
18. The article as recited in claim 15 further comprising at least
one series of weaknesses wherein said at least one series of
weaknesses is extensive through said bonding material and at least
a portion of said absorbent material.
19. The article as recited in claim 15, wherein said sheet material
exhibits a lamination efficiency of at least 10 g/m.sup.2.
20. The article as recited in claim 15, wherein said sheet material
has a basis weight from 200 pounds per 3000 ft.sup.2 (0.325
kg/m.sup.2) to 400 lb/3000 ft.sup.2 (0.651 kg/m.sup.2).
Description
FIELD OF THE INVENTION
[0001] The present invention relates to cut-resistant and absorbent
sheet materials which are suitable for protecting a supporting
surface from various articles and/or substances placed thereon and
vice-versa. The present invention further relates to such
cut-resistant and absorbent sheet materials which are also capable
of absorbing and/or containing various liquids which may be carried
by or exuded from such various articles and/or substances and
protecting the supporting surface from these liquids.
BACKGROUND OF THE INVENTION
[0002] Sheet-like materials for use in protecting objects or
substances from a supporting surface, and/or protecting supporting
surfaces from objects or substances, are well known in the art.
Such materials can be utilized to provide a permanent form of
protection, but frequently are situation or task-oriented and are
only required or utilized for a limited period of time and then
disposed of.
[0003] One common scenario for the use of such sheet materials is
the preparation of food items for consumption, such as the
preparing of certain meat products for cooking. Protective sheet
materials in this scenario may provide dual protective functions in
protecting the food item from soiling and other contamination from
a supporting surface, such as a countertop, as well as protecting
the supporting surface from soiling due to blood, water, and other
fluids and substances present on the surface of the food item.
Protective sheet materials may also protect a supporting surface
from physical damage such as impact from a sharp object or cutting
device such as a knife or cleaver used in such food
preparation.
[0004] Typically, the consumer is faced with a paradox in selecting
an appropriate sheet material for use in such a food preparation
scenario. Sheet materials which are comparatively high in
absorbency, such as paper-based materials, are typically low in
shred-resistance, while those which are comparatively high in
cut-resistance, such as plastic sheet materials, are comparatively
low in absorbency. Another disadvantage of sheet materials that are
comparatively high in absorbency is that they are difficult to
sanitize after use to prevent contamination of subsequent food
materials that contact the sheet material. This can be due in part
to cuts being made in the sheet material that cannot be readily
cleaned because of the absorbent nature of the sheet material.
[0005] Accordingly, it would be desirable to provide a sheet
material which is both comparatively high in absorbency and
comparatively high in cut-resistance, yet also comparatively thin,
light, and flexible so as to be easily disposed of. It is also
desirable to provide such a material which is also high in
shred-resistance.
[0006] It would further be desirable to provide such a sheet
material which, while durable in use, may be so readily and
economically manufactured so as to be disposed of after use and
replaced with a new and uncontaminated sheet material for a
subsequent use. This results in an increase in safety for the end
user and can prevent the spread of harmful contamination to
uncontaminated foodstuffs.
SUMMARY OF THE INVENTION
[0007] The present invention encompasses a multi-purpose sheet
material comprising an absorbent material having a top layer and a
bottom surface. The top layer comprises an amalgamation of the
absorbent material and a continuous sheet of bonding material. A
fluid impermeable material is in contact with the bottom surface.
The bonding material has a basis weight in the range of 4 g/m.sup.2
to about 100 g/m.sup.2, and, the sheet material exhibits a
lamination efficiency of at least 10 g/m.sup.2.
[0008] The present invention also encompasses a multi-purpose sheet
material comprising an absorbent material having opposing first and
second surfaces, an impermeable material in contact with the first
surface of the absorbent material, and a bonding material in
contact with the second surface of the absorbent material and
forming an amalgamated layer therebetween. The sheet material
exhibits an absorbent efficiency of at least about 0.2, a
lamination efficiency of at least 11 g/m.sup.2, and a
cut-resistance of at least 30 kgf/cm.
[0009] The present invention also encompasses an absorbent,
cut-resistant, and shred-resistant article comprising a sheet
material. The sheet material exhibits a cut-resistance of at least
30 kgf/cm, an absorbent efficiency of at least 0.2, and a
lamination efficiency of at least 10 g/m.sup.2.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] While the specification concludes with claims particularly
pointing out and distinctly claiming the present invention, it is
believed that the present invention will be better understood from
the following description in conjunction with the accompanying
Figures, in which like reference numerals identify like elements,
and wherein:
[0011] FIG. 1 is a cross sectional view of the cut-resistant and
absorbent multi-purpose sheet material in accordance with the
present invention;
[0012] FIG. 2 is a plan view of an exemplary bonding material for
use with the present invention;
[0013] FIG. 2a is a cross sectional view of the bonding material
taken along the line 2a-2a of FIG. 2;
[0014] FIG. 3 is a plan view of an exemplary absorbent material for
use with the present invention;
[0015] FIG. 3a is a cross sectional view of the bonding material
taken along the line 3a-3a of FIG. 3;
[0016] FIG. 4 is a plan view of an exemplary combination of a
bonded and combined bonding material and absorbent material of the
present invention;
[0017] FIG. 4a is a cross sectional view of a bonded and combined
bonding material and absorbent material taken along the line 4a-4a
of FIG. 4;
[0018] FIG. 4b is a magnified view of the combination of a bonded
and combined bonding material and absorbent material in area 4b of
FIG. 4;
[0019] FIG. 5 is a cross sectional view of an unbonded and combined
bonding material and absorbent material;
[0020] FIG. 5a is an magnified view of an unbonded and combined
bonding material and absorbent material in area 5a of FIG. 5;
[0021] FIG. 6 is a plan view of an exemplary process for
manufacturing the cut-resistant and absorbent sheet material of
FIG. 1;
[0022] FIG. 7 is a plan view of an exemplary sheet material having
score marks;
[0023] FIG. 7a is a cross sectional view of a tear initiation score
taken along the line 7a-7a of FIG. 7;
[0024] FIG. 7b is an expanded view of a tear initiation score of
the region labelled 7b of FIG. 7a;
[0025] FIG. 7c is an expanded view of a tear initiation score of
the region labelled 7c of FIG. 7;
[0026] FIG. 8 is a plan view of the exemplary separated sheet
material of FIG. 7;
[0027] FIG. 9 is a plan view of another exemplary separated sheet
material of FIG. 7;
[0028] FIG. 10 is a cross-sectional view of an exemplary sheet
material showing an exemplary score;
[0029] FIG. 9 is a cross-sectional view of another exemplary sheet
material showing an exemplary score; and,
[0030] FIG. 12 is a cross-sectional view of another exemplary sheet
material showing an exemplary score.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0031] As utilized herein, the term "Absorbent Efficiency" is used
to refer to a derived parameter for measuring absorbent properties
which has been found useful to characterize sheet materials and
determine whether they perform satisfactorily in the food
preparation environment. The Absorbent Efficiency takes absorption
rate, absorbent capacity, and thickness of the sheet material into
account.
[0032] In a disposable food preparation sheet, it is desirable to
absorb a sufficient quantity of fluid in a reasonable period of
time. It is also desirable for the sheet material to be relatively
thin to maintain good conformability to a supporting surface and to
have an impression of disposability. Thus, the absorbent efficiency
can be maximized by maximizing the absorbent capacity, the rate of
absorbtion, and minimizing the sheet material thickness.
[0033] As utilized herein, the term "Cut-resistance" is used to
refer to a derived parameter which has been found useful to
characterize sheet materials and determine whether they perform
satisfactorily in the food preparation environment. Based on
extensive consumer testing, a food preparation mat should have a
cut-resistance of at least 30 kgf, as measured using the
cut-resistance test discussed below, so that an average consumer
will not cut through the protective surface during a single
use.
[0034] As utilized herein, the term "Lamination Efficiency" is used
to refer to a derived parameter which has been found useful to
characterize sheet materials and determine whether they perform
satisfactorily in the food preparation environment. Lamination
Efficiency relates to the integrity of the structure when it is cut
during use and measures the effectiveness of incorporation of the
bonding material to the absorbent material which could otherwise
shred or come loose during typical use. Lamination Efficiency is
the amount of mass gained by the bonding material after exerting a
force that separates the bonding material from the absorbent
material at the adhered interface, at a separation angle of
180.degree., and a constant rate of separation of 40 inches/minute
(102 cm/min). Ultimately, Lamination Efficiency is the comparison
of the mass per area of the peeled material versus the mass per
area of the raw bonded material and is at least 10g/m.sup.2. A
sheet material can also have a satisfactory performance if the
prepared sample tears during determination of the Lamination
Efficiency.
[0035] FIG. 1 depicts one embodiment of a cut-resistant and
absorbent multi-purpose sheet material (sheet material) 10 in
accordance with the present invention. Sheet material 10 includes
an absorbent material 11 which functions as a fluid reservoir, an
impermeable material 12, and a bonding material 13 which preferably
extends continuously across the surface of absorbent material 11.
Sheet material 10 is shown in an orientation suitable for placement
upon a supporting surface (not shown), such as a countertop or
table, with the impermeable material 12 in contact with the
supporting surface and the impermeable material 12 facing outwardly
from the supporting surface. Sheet material 10 may also include an
optional adhesive system (not shown) on the outwardly-facing
surface of the impermeable material 12 which would be placed in
contact with a supporting surface.
[0036] As shown in FIG. 1, sheet material 10 preferably comprises a
generally planar sheet-like structure of the desired planar
dimensions and having two opposed principal surfaces which are
likewise substantially planar. "Layers" of such a sheet material
are also typically substantially planar, coextensive, and/or define
planes of contacting surfaces. However, it would be known to one
skilled in the art that other geometries could be used. Impermeable
material 12 preferably fully covers one surface of absorbent
material 11, such that any fluids contained therein cannot pass
through the impermeable material 12 and onto any supporting surface
upon which the sheet material 10 is placed. Bonding material 13
preferably extends across the surface of the absorbent material 11
opposite from the impermeable material 12, forming a regular
repeating pattern of elements.
[0037] Since bonding material 13 is preferably thermally heated to
facilitate attachment to absorbent material 11, a region, or layer,
of amalgamation 14 forms between bonding material 13 and absorbent
material 11. In a preferred embodiment, the bonding material 13 is
heat bonded to the web fibers of absorbent material 11 so that the
heated bonding material 13 forms a discontinuous pattern of
adhesion with the individual fibers. This discontinuous bonding of
absorbent material web and bonding material will have a
discontinuous depth of penetration into the absorbent material
11.
[0038] As shown in FIG. 1, bonding material 13 (shown as a scrim or
woven-like structure and depicted in FIGS. 2 and 2a) is preferably
laminated to absorbent material 11 (shown in FIGS. 3 and 3a) by a
combination of heat and/or pressure to form amalgamated layer 14.
During the amalgamation process, a substantial reduction in the
combined thickness of the absorbent and bonding materials 11, 13
occurs. Without wishing to be necessarily bound by theory, it is
believed that the bonding material 13 flows both parallel and
perpendicular to the large or planar dimensions of the absorbent
material 11. This substantial reduction in thickness is
representatively shown by comparing the individual thickness of the
bonding material and absorbent material (depicted as adjacent
layers in FIG. 5) to the corresponding heat and pressure processed
structure (shown in FIG. 4a).
[0039] Absorbent Material
[0040] The absorbent material may be formed from any material or
materials suitable for forming an absorbing structure having
interstitial regions suitable for absorbing or transporting fluid
by capillary action. Additionally, the component fibers or other
material may be absorbent. Exemplary suitable materials include
materials formed from natural fibers, such as cellulosic fibers or
refined cellulosic fibers, and/or synthetic fibers, including
hollow fibers and capillary channel fibers. As an alternative to or
in combination with such fibers, the absorbent material 11 can
include an absorbent polymeric foam material, an absorbent
polymeric gelling material, a hydrogel material, and/or natural
starches and gums, for example. Materials of particular interest
include cellulosic substrates, such as paperboard from SSK
(Southern Softwood Kraft), NSK (Northern Softwood Kraft), or
hardwood fibers such as eucalyptus cellulosic fiber fluff such as
are typically used in paper manufacturing. The absorbent material
11 can alternatively comprise a non-woven substrate, such as can be
constructed by entangling synthetic fibers, for instance. The
absorbent material may comprise one monolithic layer of material or
may comprise a laminate structure having multiple layers of the
same or different composition. In addition, the absorbent material
may comprise a carrier web that itself may or may not be absorbent,
but may carry an absorbent material. The role of the absorbent
material in the sheet materials of the present invention is to
absorb and sequester fluids.
[0041] Preferably, the web material forming the absorbent material
11 has a relatively high dry basis weight. For example, dry basis
weights of in the range of 200 pounds per 3000 ft.sup.2 (0.325
kg/m.sup.2) to 400 pounds per 3000 ft.sup.2 (0.651 kg/m.sup.2) are
preferred to provide adequate cut-resistance and absorbency. More
preferably, the dry basis weight of the absorbent material 11 is in
the range of 220 pounds per 3000 ft.sup.2 (0.358 kg/m.sup.2) to 280
pounds per 3000 ft.sup.2 (0.456 kg/m.sup.2) and most preferably the
dry basis weight of the absorbent material is about 240 pounds per
3000 ft.sup.2 (0.391 kg/m.sup.2).
[0042] If desired for particular applications, the absorbent
material 11 or any other elements of the sheet material 10 of the
present invention may contain or incorporate certain active
materials which act upon the object or substance placed upon the
sheet material 10, and/or upon the fluids carried by or exuded from
the object or substance. Non-limiting actives may comprise agents
intended to neutralize, sequester, disinfect, deodorize, or
otherwise modify the properties of solid or liquid materials or the
atmospheric environment surrounding the sheet material 10 during
use. Particular agents of interest would be those which modify the
behavior of fluids such as aqueous fluids, blood-based fluids,
oils, etc. Typical properties which may be desirable for certain
applications are deodorant properties, antimicrobial properties,
coagulating properties, etc. Exemplary materials include baking
soda, fibrinogen, and other materials in suitable form for
inclusion.
[0043] Bonding Material
[0044] Preferably, the bonding material 13 may be formed from any
material or materials suitable for forming a continuous network or
a discontinuous array of discrete elements of the desired size,
shape, and spacing. In accordance with the present invention, the
bonding material 13 is preferably synthetic. The bonding material
13 may be formed from and/or treated with a material which tends to
cause the fluids of interest to "wet out" on the surface, for
example, hydrophilic materials. Suitable bonding materials 13
include polymers, polymeric film bonded or laminated to the
absorbent material, thermoplastic, or crosslinked resins directly
cast, printed, or extruded onto the absorbent material, coated
paper or cardboard bonded to the absorbent material 11 by adhesives
or the like, etc. The bonding material 13 may comprise one
monolithic layer of material, a mixed fiber layer of material, or a
laminate structure having multiple layers of the same or diverse
composition. Bonding material 13 may have any desired caliper
suitable for a particular application.
[0045] Preferably, thermoplastic materials utilized for the bonding
material 13 have a low enough melting temperature, T.sub.m, such
that it will soften at temperatures which will not cause the
absorbent material 11 to char or burn during the application of
heat to effect amalgamation. Such a material can thereby be bonded
to the absorbent material 11 through the application of heat and/or
pressure.
[0046] The bonding material 13 is preferably formed from a material
which is durable in use, resilient, and/or
scuff/abrasion-resistant. Typical materials which are known in the
art as exhibiting such properties may be utilized, including those
which typically exhibit a high degree of toughness, interlocked
molecular structure of comparatively high molecular weight
material, and comparatively high coefficient of sliding friction.
Suitable materials include polymeric materials, such as ethylene
vinyl acetate (EVA), high density polyethylene (HDPE), low density
polyethylene (LDPE), linear low density polyethylene (LLDPE),
polyvinyl chloride (PVC), plastisols, polypropylene (PP),
polyethylene terepthalate (PET), crystallized PET, polybutylene
teraphthalate (PBT), polyethylene naphthalate (PEN), other
polyolefins, polyurethanes, paper materials, epoxies, thermosets,
inorganic fillers or fibers, mineral fibers, etc. Preferably, the
bonding material 13 is selected to have a pre-applied basis weight
of from 4 g/m.sup.2 to 100 g/m.sup.2, and more preferably from 15
g/m.sup.2 to 50 g/m.sup.2. Additionally, the bonding material 13 is
preferably selected to have a post-lamination open area of at least
0.5 percent, more preferably 20 percent, and most preferably 35
percent. The measure of the open area is the measure of the surface
area of the absorbent material not in communication with bonding
material. The open area maintains communication for the absorbent
material to absorb or provide passage of a juice or liquid from the
surface of sheet material 10 to the absorbent material 11.
[0047] As noted above, the bonding material 13 could also comprise
compounded polymeric materials. For example, tough inorganic
fillers can also be provided in combination with one or more
polymers to form the bonding material 13, in order to reduce the
cost of the bonding material 13 and/or change particle toughness,
density, cut-resistance, color, or other property. Suitable fillers
include CaCO.sub.3, talc, and mica, for example. However, although
particulates and fillers can be used to form bonding material 13,
it is preferred that absorbent material 11 is substantially free of
inorganic free filler particulate. As used herein, the term "free
filler particulate" refers to inorganic particles which are not
bonded to the absorbent material 11 and which merely reside freely
within the absorbent material 1. Such a material may be released
from the sheet material 10 during cutting operations and be mixed
with the food items being prepared, potentially making the food
undesirable in appearance and/or unsuitable for consumption. It is
also preferable that the absorbent material 11 is substantially
free of organic free filler particulate which is not suitable for
contact with food items. Organic free filler particulate does not
refer to the absorbent material 11, such as cellulosic fibers and
the like as described herein. By "substantially free" what is meant
is an amount no greater than that which would be safe for use of
the absorbent material 11 in food preparation, or less than an
amount in which the filler particulate released during food
preparation is noticeable by visual or tactile inspection of the
absorbent material 11 or food items, or both. By tactile
inspection, what is meant is tactile sensory via the hand, or, with
respect to food items, the mouth. Preferably, 0% of such free
filler particulate is added to the absorbent material 11. If free
filler particulate is included, however, the level should
preferably be no greater than about 10%, more preferably no greater
than about 5%, more preferably no greater than about 2%, more
preferably no greater than about 1%, more preferably no greater
than about 0.5%, and most preferably no greater than about 0.1% by
weight of the dry sheet. Notwithstanding the above, the sheet
material 10 hereof can be substantially free of free filler
particulate if it contains unbonded particulate material, but none
of the particulate material is releasable when the sheet material
10 is used as intended (i.e., by placing a food item on the side of
the sheet intended to be used for cutting, and cutting the food
item while it is on this side of the sheet.) Thus, the sheet
material 10 can be substantially free of filler particulate when it
includes unbonded particulate material which is positioned or
configured such that little or none is released from the cutting
surface during cutting.
[0048] Without wishing to be bound by theory, for the majority of
bonding materials, there is a substantial flow of the bonding
material 13 parallel to the absorbent material 11 as shown in FIG.
4a. Additionally, there is a flow or penetration of the bonding
material 13 into the absorbent material 11 perpendicular to the
large dimensions of the absorbent material 11. The resulting
penetration of the bonding material 13 into the absorbent material
11 is somewhat non-uniform corresponding to the non-uniformity of
the absorbent material 11. For example, wet laid paper manufacture
using a Fourdrinier paper machine are known to be capable of
producing a very smooth and uniform paper. However, fiber density
is not uniform across very small dimensions approaching the
individual fiber diameter. While surface roughness and
non-uniformity are preferably reduced as higher levels of paper
smoothness are obtained, often through calendaring, variations in
fiber density routinely result in more dense and less dense regions
of the final paper or absorbent material. As a consequence of
non-uniform regions of paper density, the combination of heat and
pressure applied during a laminating process can cause the flow of
bonding material 13 to be non-uniform over regions of the bonding
material 13 and absorbent material 11 interface of dimensions
approaching the individual fiber dimensions of the absorbent
material 11 fiber. FIG. 5a shows a cross-sectional view of the
bonding material 13 adjacent and non-laminated to the absorbent
material 11. FIG. 5a shows variation in the density of the
absorbent material 11 as shown by number of fibers. FIG. 4b shows
an exemplary non-uniform interface existing between the bonding
material 13 and the absorbent material 11 after an efficient
lamination.
[0049] As shown in FIG. 4b, the non-uniform interface between the
bonding material 13 and absorbent material 11 is comprised of an
amalgam of both the bonding material 13 and absorbent material 11
formed as the bonding material 13 flows perpendicular and into the
thickness or small dimension of the absorbent material 11. Bonding
material 13 consequently flows between fibers and especially into
the lower density regions within the localized non-uniform lower
density regions of the absorbent material 11. This amalgamated
layer 14 integrates a portion of the paper fibers into the bonding
material 13 resulting in an effective lamination which achieves a
peel strength substantially equal to that of the internal strength
of the absorbent material 11. An effective lamination is
characterized by the absorbent material 11 being bonded to the
bonding material 13 so that the absorbent material 11 is integrated
into the bonding material 13. When well integrated, the bonding
material 13 cannot be delaminated or peeled from the aborbent
material 11 without either substantial mass loss from the absorbent
material 11 or incomplete peeling as the combined bonding and
absorbent materials break without substantial peeling. This
incomplete peeling, resulting in tearing or breaking, occurs when
the bonding material 13 is well integrated with the absorbent
material 11 and has a tear strength equal to or less than the
internal strength of the paper. This characterization is expressed
by a satisfactory Lamination Efficiency and is determined by the
test method discussed infra.
[0050] Impermeable Material
[0051] The impermeable material 12 is generally used as a backing
sheet and may preferably be formed from any material or materials
suitable for forming a continuous layer or coating on a surface of
the absorbent material 11 which is impervious to fluids of
interest. Suitable materials include polymeric films bonded,
amalgamated, or laminated to the absorbent material 11,
thermoplastic resins directly cast, extruded, or thermoformed onto
the absorbent material, metallic foils, or other impervious
coatings printed, coated, hot-pressed, sprayed, adhered, or
otherwise topically applied. The impermeable material 12 can also
be applied during manufacture of the absorbent material 11. The
impermeable material 12 may comprise one monolithic layer of
material or may comprise a laminate structure having multiple
layers of the same or diverse composition. Impermeable material 12
preferably has a high coefficient of friction to facilitate
immobility to a support surface and is preferably coextensive with
absorbent material 11 to prevent the release of absorbed fluids
from the absorbent material 11 to a support surface.
[0052] An optional, or additional, adhesive system may comprise a
zonal, patterned, discrete, or continuous coating or layer of a
pressure sensitive adhesive or any other adhesive system known in
the art to provide for an adhesive force between the sheet material
10 and a supporting surface. This optional feature provides
additional lateral stability over and above the friction between
the impermeable material and the supporting surface. Release liners
or other configurations may be desired depending upon the tack of
the adhesive and/or the construction of the sheet material. Other
configurations may utilize a non-adherent but comparatively high
coefficient of friction material which resists sliding upon most
typical supporting surfaces.
[0053] Sheet Material
[0054] In use, the sheet material 10 is placed upon a supporting
surface such as a countertop, tabletop, or floor surface and an
object or substance is placed thereon. The object or substance may
be a food item or any other item of interest which is to be
manipulated or otherwise handled or treated during the course of
any operation. The sheet material 10 could also be utilized for
storage of an object to collect residual fluids such as in the case
of thawing frozen foods. After use or when the absorbent material
11 has become sufficiently contaminated or saturated with fluids,
the sheet material may be disposed of in a responsible manner.
[0055] Preferably, sheet material 10 has a thickness t ranging from
250 .mu.m (0.01 inch) to 1270 .mu.m (0.05 inch) to provide adequate
cut-resistance and absorbency. If paper making processes and
machinery are used to produce the sheet 10, manufacturing
parameters such as material application rate, amount and duration
of pressure applied, etc. can be adjusted to manipulate the basis
weight and thickness of the resulting sheet 10.
[0056] The sheet material 10 is preferably sufficiently flexible
and conformable such that it will conform to somewhat irregular or
profiled supporting surfaces. For certain dispensing or packaging
configurations, it may also be desirable for the sheet material 10
to be sufficiently conformable in one or more directions such that
it may be rolled upon itself to form a more compact configuration.
Selection of materials for respective elements of the sheet
material 10, as well as maintaining a comparatively low bending
modulus via appropriate structural design (small cross-section,
minimal thickness normal to the plane of the sheet material,
discontinuous pattern, etc.), aids in obtaining the desired degree
of flexibility.
[0057] Additional absorbent capacity and protection of underlying
and surrounding surfaces may also be provided in the form of a
highly absorbent border at the periphery of the sheet material 10,
a lip around the marginal edge, or other suitable techniques.
[0058] It may be desirable for certain applications to include a
color-changing feature to the sheet material 10 to indicate a
change in condition of the sheet occurring during use. For example,
it may be desirable to include a color-changing composition in the
sheet material 10 whereby the absorbent material 11 changes color
when it absorbs fluid. Additionally, colors of respective sheet
elements may be selected such that the bonding material 13 and
absorbent material 11 are initially the same color, such as white,
until the absorbent material 11 changes to a contrasting color,
such as red. One method of accomplishing such a color change is to
incorporate a food grade additive or other pigmented powder, either
within or underneath the absorbent material 11. When the pigmented
powder is exposed to fluid it dissolves in the fluid and "bleeds"
into the absorbent material 11 and changes the apparent color of
the absorbent material 11. Color change may be triggered by the
occurrence of other physical changes in functionality, such as
depletion of an anti-microbial agent, or presence of bacteria,
within the absorbent material. One method believed suitable for
such an execution is disclosed in U.S. Pat. No. 4,311,479, issued
Jan. 19, 1982 to Fenn et al., the disclosure of which is hereby
incorporated herein by reference.
[0059] Although for some applications a compartmentalized absorbent
material 11 distribution may be desirable, it is presently
preferred for most applications to utilize a continuous absorbent
material 11 so as to provide for the maximum level of
absorbency.
[0060] Sheet materials 10 in accordance with the present invention
may be deployed in a wide variety of scenarios and utilized for a
wide variety of functions. Representative products made from sheet
materials 10 include, but are not limited to, place mats, food
preparation mats, mats for draining washed or cooked food, floor
mats, drawer and shelf liners, etc. Objects of interest may include
food items such as cuts of meat, produce, baked goods, produce such
as fruits and vegetables, etc.
[0061] In accordance with the present invention, sheet materials 10
such as those depicted in the foregoing discussion of drawing
figures exhibit comparatively high levels of absorbency,
shred-resistance, and cut-resistance, more particularly, lamination
efficiency and absorbent efficiency.
[0062] Scoring
[0063] As shown in FIG. 7, at least one series of weaknesses,
weakened zones, or lines of weakness 26, 27, such as score lines,
lines of perforation, or intermittent scores, can be employed on
sheet material 10 if desired to add additional flexibility and/or
to promote folding or bending of sheet material 10 in certain
directions or regions. These weaknesses 26, 27 can be incorporated
in the sheet material 10 to facilitate separation of the sheet
material 10 into distinct pieces amenable for use with smaller
items. As shown in FIGS. 8 and 9, the sheet material 10 can
therefore, be scored to affect a separation into two or more
fragments. Likewise, as would be known to one of skill in the art,
many other patterns can be scored to effect decorative separations
of sheet material 10. This advantage provides a single sheet for
use with multiple items without risking contamination of the
remainder of a single sheet.
[0064] Intermittent scoring can be accomplished by substantially
reducing the integrity of the absorbent and bonding materials, thus
facilitating separation of a sheet section by the user applying a
tearing action. Additionally, as shown in FIGS. 10-12, intermittent
score 25a, 25b, 25c are preferably spaced so that the
cut-resistance of the bonding material 13, amalgamated layer 14,
absorbent material 11, and impermeable material 12 is substantially
preserved. However, as would be known to one of skill in the art,
the score depth and spacing of scores 25a, 25b, 25c can be adjusted
to provide ease of sheet separation and maintain cut-resistance.
Additionally, the score depth can be controlled so that the bonding
and absorbent materials may be partially cut through their
thickness 25a, or entirely through their thickness 25b, 25c, so
that the impermeable material 12 is either entirely 25a, 25b or
partially 25c in tact.
[0065] A consideration in determining individual score length is
the geometry of cutting implements which may come in contact with
the sheet, for example, serrated knives. The size of the individual
scores can be adjusted so that the protrusions forming the serrated
shape of such a knife will not easily fit within the length and
width of the score.
[0066] Thus, it is preferred that a sheet material have one or more
intermittent scores with an individual score length of between 0.01
inches (0.25 mm) and 0.5 inches (12.7 mm), more preferably between
0.02 inches (0.50 mm) and 0.1 inches (2.54 mm), and most preferably
between 0.03 inches (0.76 mm) and 0.05 inches (0.13 mm). It is also
preferred that the scores have a repeated space between score lines
of between 0.01 inches (0.25 mm) and 0.5 inches (12.7 mm), more
preferably between 0.02 inches (0.50 mm) and 0.1 inches (2.54 mm),
and most preferably between 0.03 inches (0.76 mm) and 0.05 inches
(1.27 mm).
[0067] It is also preferred that the scores have a depth of scoring
partially through the bonding and absorbent materials 13, 11 or
entirely through the bonding and absorbent materials 13, 11 and up
to or partially through the impermeable material 12. Thus, a score
would extend from one side of the sheet material 10 through the
sheet material thickness leaving an unscored thickness longitudinal
to the score of between 0.0001 inches (0.0025 mm) and 0.025 inches
(0.64 mm), more preferably between 0.0075 inches (0.19 mm) and
0.0125 inches (0.32 mm), and most preferably between 0.001 inches
(0.025 mm) and 0.03 inches (0.76 mm) for a sheet material 10 having
a thickness ranging from 0.01 inch (250 .mu.m) to 0.05 inch (1270
.mu.m).
[0068] As shown in FIG. 7b, in order to initiate tearing of the
sheet material 10 into separate sections, it is generally desirable
to include a tear initiation score 25d which extends through the
impermeable material 12 at the edge of the sheet material 10.
Without wishing to be bound by theory, it is believed that tear
initiation score 25d assists in the propagation of a tear in the
impermeable material 12. This reduces the force required to
initiate a tear, the potential for non-tear deformation, and the
potential for separation of the impermeable material 12 from the
absorbent material 11 when it is desired to separate the sheet
material 10 into different sections.
[0069] As shown in FIG. 7c, tear initiation score 25d can vary in
length from the edge 25e of the sheet material 10 according to the
specific use intended so that it does not substantially interfere
with the impermeable benefits of the sheet material 10. It is
preferred that tear initiation score 25d have a length between
0.005 inches (0.127 mm) and 1.0 inches (25.4 mm), more preferably
between 0.05 inches (1.27 mm) and 0.5 inches (12.7 mm), and most
preferably between 0.1 inches (2.54 mm) and 0.375 inches (9.53
mm).
[0070] Manufacture
[0071] FIG. 6 illustrates a suitable process and equipment for
producing the sheet material 10 according to the present invention.
Continuous webs of the absorbent material 11 and the bonding
material 13 are fed from a spool or roll 22, 21 respectively. The
two continuous webs or sheets 11, 13 are fed together through the
hot press 20 to bond or laminate absorbent material 11 with bonding
material 13 at laminating station 23. At laminating station 23,
melted bonding material 13, due to the resulting pressure from
middle roll 15 and top roll 16 laminates the bonding material 13
into the top surface of the absorbent material 11. This applied
heat and pressure causes bonding material 13 to flow into absorbent
material 11 to form amalgamated layer 14. Likewise, a heated band
press, or other heated press apparatus as would be known to one of
skill in the art, could also be utilized for the lamination
process.
[0072] Preferably, the individual webs are heated as they pass over
the heated middle roll 15 of the laminating station 23. Heating
middle roll 15 may allow the process to run at higher speeds.
Without wishing to be bound by theory, it is believed that the
polymeric nature of thermoplastic bonding material 13 causes
bonding material 13 to shrink in size upon the application of heat.
Therefore, the frictional forces present on the surface of
absorbent material 11 constrain movement of bonding material 13
caused by the heating of bonding material 13 and any subsequent
polymeric matrix degradation and shrinkage. Thus, individual webs
11, 13 are preferably wrapped around the middle roll 15 so that the
bonding material 13 is in direct contact with the heated middle
roll 15. Additionally, middle roll 15 is preferably treated with a
release coating to prevent the bonding material 13 from sticking to
middle roll 15 as it melts.
[0073] An impervious material 12 is then preferably applied to the
sheet 17. This can preferably be accomplished by application of a
coating to the sheet 17 by extrusion coating station 18 as would be
known to one skilled in the art. The extrusion coating station 18
coats the unlaminated surface of the sheet 17 with a film of molten
polymer 12a. The molten polymer film 12a bonds with the sheet 17
creating the sheet material 10a.
[0074] The web sheet material 10a is next preferably routed to a
die-cutting station 19. The die-cutting station 19 preferably
utilizes a rotary die-cutting tool to cut the web sheet material
10a into individual sheets 10 or provide a scoring line or lines to
sheet material 10. Exemplary absorbent materials, bonding
materials, line speeds, process temperatures and pressures for
producing exemplary sheets in accordance with the present invention
are detailed in Table 1.
1TABLE 1 Exemplary Process Materials, Line Speeds, Temperatures and
Pressures Middle Bottom Line Roll Roll Nip Absorbent Bonding Speed
Surface Surface Force Material Material (m/min) Temp(.degree. C.)
Temp(.degree. C.) (N/m) 100% 15 g/m.sup.2 60.96 209 98 18388 NSK, 9
denier, 0.559 mm poly- thick, propylene 0.406 kg/ carded m.sup.2
Paper- nonwoven board 100% 48.9 g/m.sup.2 12.19 213 114 23817 NSK,
poly- 0.559 mm propylene Thick, scrim 0.406 kg/ m.sup.2 Paper-
board 100% 34.2 g/m.sup.2 24.38 211 141 23817 NSK, poly- 0.559 mm
propylene Thick, scrim 0.406 kg/ m.sup.2 Paper- board
Test Methods
[0075] The following test methods have been developed and utilized
for characterizing the sheet materials in accordance with the
present invention.
[0076] Absorbent Rate:
[0077] 1) A 4 in. by 4 in. (10.16 cm by 10.16 cm), 16 in.sup.2
(103.2 cm.sup.2), sample of sheet material is preconditioned in a
controlled temperature environment of 140.degree. F. (60.degree.
C.) and 0% relative humidity for 24 hours. The sheet material
sample is then conditioned in controlled temperature and humidity
environment of 73.degree. F. (22.78.degree. C.) and 50% relative
humidity for 24 hours.
[0078] 2) Weigh and record the initial weight of each conditioned
sample.
[0079] 3) Measure and record the sheet thickness of each
conditioned sample.
[0080] 4) Calculate and record the average sheet thickness of the
conditioned samples.
[0081] 5) Place the weighed and conditioned sample on a clean, flat
testing surface directly under and 2 inches (5.08 cm) from a Buret
containing 5 cc of distilled water so that the water will be
dispensed onto the large dimension of the sample.
[0082] 6) Dispense the distilled water from the Buret onto the
conditioned sample.
[0083] 7) Let the sample absorb all or a portion of the water for
30 seconds. If all water is absorbed prior to 30 seconds, record
this time of absorption.
[0084] 8) At 30 seconds the sample is held on an edge perpendicular
to the clean flat testing surface, and gently tapped by raising it
perpendicularly 1 in (2.54 cm) above the testing surface and back
down to the testing surface. This is repeated 10 times at 1 second
intervals to remove any visible, non-absorbed water remaining on
the sample surface.
[0085] 9) Weigh the sample and record the sample final weight.
[0086] 10) The Absorbent Rate is calculated as (final
weight-initial weight)/time (the observed absorption time or 30
seconds, whichever is shorter). The derived units of Absorbent Rate
are 1 g water s .
[0087] 11) Calculate the unit absorbency rate as ((final
weight-initial weight)/time)/sample area. The units are 2 g water s
cm 2 .
[0088] 12) Repeat this test on 2 new samples of sheet material,
prepared as above.
[0089] 13) Record the average of sample values and report as
"Absorbent Rate".
[0090] Absorbent Capacity:
[0091] 1) A 4 in. by 4 in. (10.16 cm by 10.16 cm), 16 in.sup.2
(103.2 cm.sup.2), sample of sheet material is preconditioned in a
controlled temperature environment of 140.degree. F. (60.degree.
C.) and 0% relative humidity for 24 hours. The sheet material
sample is then conditioned in controlled temperature and humidity
environment of 73.degree. F. (22.78.degree. C.) and 50% relative
humidity for 24 hours.
[0092] 2) Weigh and record the initial weight of each conditioned
sample.
[0093] 3) Measure and record the sheet thickness of each
conditioned sample.
[0094] 4) Calculate and record the average sheet thickness of the
conditioned samples.
[0095] 5) Completely submerge the pre-weighed and conditioned
sample in a 5 gallon (18.93 1) container containing at least 1
gallon (3.785 1) of distilled water for 120 sec.
[0096] 6) Remove the sample from the container by holding a
corner.
[0097] 7) Hold the sample perpendicular to the container for 30
seconds to remove any unabsorbed water.
[0098] 8) Weigh the sample and record the final weight.
[0099] 9) Calculate the Absorbent Capacity as (final weight-initial
weight)/sample area. The units are 3 g water cm 2
[0100] 10) Repeat this test on 2 new samples of sheet material,
prepared as above.
[0101] 11) Calculate the average absorbent capacity values and
report as "Absorbent Capacity".
[0102] Absorbent Efficiency:
[0103] 1) Calculate the Absorbent Efficiency as: 4
AbsorbentEfficiency = AbsorbentCapacity AbsorbentRate
sheetthickness * 10 4
[0104] where Absorbent Capacity has units of 5 g water cm 2 ,
[0105] Absorbent Rate has units of 6 g water s cm 2 ,
[0106] sheet thickness has units of cm, and the Absorbent
Efficiency has units of 7 ( g water cm 2 ) ( g water s cm 2 ) ( 1
cm ) .
[0107] Cut-Resistance
[0108] The test apparatus described applies a known force in the z
(vertical) direction on a knife blade to measure the cut-resistance
of a sample when a force is directly applied.
[0109] 12) A 6 in. by 8 in. (15.24 cm by 20.32 cm), 48 in.sup.2
(309.7 cm.sup.2), sample of sheet material is preconditioned in a
controlled temperature environment of 140.degree. F. (60.degree.
C.) and 0% relative humidity for 24 hours. The sheet material
sample is then conditioned in a controlled temperature and humidity
environment of 73.degree. F. (22.78.degree. C.) and 50% relative
humidity for 24 hours.
[0110] 1) Measure and record the sheet material thickness of each
conditioned sample.
[0111] 2) A Personna Poultry Blade, Code # 88-0337, or equivalent,
is placed in the knife holder of the cut-test apparatus.
[0112] 3) The conditioned test sample is affixed to the sample
platform of the cut-test apparatus.
[0113] 4) The knife blade is then brought into contact with the
affixed sample.
[0114] 5) A known load is applied to the center edge of the knife
blade.
[0115] 6) The sample platform is moved at a rate of 8 in/sec (0.203
m/sec) for 4 inches (10.16 cm) under the weight of the knife blade.
This is defined as a slice.
[0116] 7) Remove the sample from the sample platform to visually
inspect the slice for a "cut through." A cut through is defined as
a slice that has penetrated completely through the sample sheet any
length within the 4 in (10.16 cm) distance. A cut through is
visually detectable by carefully observing the front and back of
the sample sheet in a well-lighted area.
[0117] 8) Record observations. If there is a cut through, then
decrease the force by a maximum of 0.5 lbs (226.8 gm force). If
there is not a cut through then increase the force by a maximum of
0.5 lbs (226.8 gm force).
[0118] 9) Remount the sample sheet on the sample platform.
[0119] 10) Adjust the sample platform to assure a cut in a
different region of the sample sheet.
[0120] 11) Record the mininum knife force required to penetrate
completely through the sample as the "Cut Through Force" (kg).
[0121] 12) Repeat consecutive series of cuts until a minimum Cut
Through Force is noted and report the average value for three
distinct samples.
[0122] 13) "Cut-resistance" is calculated as the Cut Through Force
divided by the average Sheet Thickness (cm).
Cut-Resistance=Cut Through Force (kg)/Sheet Thickness (cm)
[0123] Lamination Efficiency
[0124] Lamination Efficiency evaluates the lamination of the
bonding material, having a known basis weight (BW), to the
absorbent material.
[0125] Lamination Efficiency Sample Preparation:
[0126] 1) Three 8 in by 1 in (20.32 cm by 2.54 cm), 8 in.sup.2
(51.61 cm.sup.2), specimens of sheet material are preconditioned in
a controlled temperature environment of 140.degree. F. (60.degree.
C.) and 0% relative humidity for 24 hours. The sheet material
sample is then conditioned in controlled temperature and humidity
environment of 73.degree. F. (22.78.degree. C.) and 50% relative
humidity for 24 hours.
[0127] 2) Measure and mark the center line width (0.50 in (1.27
cm)) of each specimen.
[0128] 3) Measure along the centerline 1 inch (2.54 cm) from a 1
inch (2.54 cm) edge and mark a cross-width line.
[0129] 4) Using a sharp cutting blade suitable for cutting through
the sample material, cut a line from the measured and marked center
of the sample edge to the marked and measured 1 in (2.54 cm)
line.
[0130] 5) Repeat for the other side of the specimen on the same end
of the sample.
[0131] 6) The material remaining with the specimen after both cuts
should now form a "V" by subtending an angle of 30.degree. on
either side of the measured longitudinal center line.
[0132] 7) Apply 0.00496 lbs (2.25 grams) of an adhesive containing
acetone and a petroleum distillate, for example, Dyna Systems
Quick-Flex general purpose adhesive, product number 672-02-500,
evenly across the entire non-laminated side of each specimen.
[0133] 8) Align and adhere the remaining squared end of the
adhesively treated specimen, with the edge of a 10 in by 1 in by
0.125 in (25.4 cm by 2.54 cm by 0.3175 cm) stainless steel metal
plate.
[0134] Pressure Sensitive Adhesive Tape Preparation:
[0135] 1) Provide a 39 in by 2 in (99.06 cm by 5.08 cm) pressure
sensitive adhesive tape having a Tappi T 540 om-93 Peel Force of a
minimum of 6.86 lbs. (3112 g) when adhered to a stainless steel
plate, for example, SpectTape.RTM., Inc. ST260 Silver Cloth Duct
Tape pressure sensitive tape. The minimum peel force of the tape
required may vary according to the surface properties and geometry
of the top layer or bonding material of the sheet material. The
purpose of having a high peel force tape is to ensure sufficient
adhesion to the sheet material to fully delaminate the material in
the area of contact. If the tape does not adhere sufficiently in
the contact area to cause delamination the test is not valid and a
tape having a higher peel force will be necessary.
[0136] 2) Fold the tape upon itself with the adhesive side inward,
leaving 1 lineal inch (2.54 cm) of adhesive exposed.
[0137] 3) Adhere the exposed 1 in (2.54 cm) of pressure sensitive
adhesive tape to the "V" cut edge of the specimen.
[0138] 4) Place a 20 lb (9.0 kg) mass on the pressure sensitive
adhesive tape adhered to the "V" cut edge of the specimen for 60
sec.
[0139] Test Procedure:
[0140] 1) Insert the un-adhered 2 in (5.08 cm) portion of the metal
plate holding the specimen into the stationary clamp of a tensile
strength test machine, such as an Instron.RTM. (model 550R/1122),
or equivalent.
[0141] 2) Insert the folded over portion of the pressure sensitive
adhesive tape into the other (Z direction) clamp of the tensile
strength test machine.
[0142] 3) Move the upper clamp away from the stationary clamp at
180.degree. and 0.667 ft/sec (0.2032 m/sec) to peel the bonding
material and the amalgamated layer from the absorbent material.
[0143] 4) Record observations such as breakage of the bonding
material where any of the bonding material, amalgamated layer, or
the absorbent material did not maintain the original 1 in by 8 in
(2.54 cm by 20.32 cm) starting dimension. As discussed in the tape
sample preparation section of this method, in the event the tape
does not delaminate the sheet material in the area of contact the
test is not valid and a more strongly adhering tape must be
used.
[0144] 5) After testing, retrieve the used pressure sensitive tape
for observations.
[0145] 6) In the event there is incomplete peeling denoted by less
than the entire sample area being delaminated, then the sample
passes the lamination efficiency test and the bonding layer is
considered well integrated with the absorbent layer. Record the
result as "pass". A "pass" is considered to meet the minimum
requirement of a sample of sheet material having a Lamination
Efficiency of at least 10 g/m.sup.2.
[0146] 7) If the sample peels away and delaminates over the entire
sample area, then cut the peeled away bonding material, amalgamated
layer, and absorbent material from the used pressure-sensitive
tape.
[0147] 8) Measure and record the area (m.sup.2) of the bonding
material, amalgamated layer, or absorbent material that was peeled
away by the pressure sensitive tape during the test. This is called
Area.sub.(peeled).
[0148] 9) Measure and record the mass (g) of the bonded material,
amalgamated layer, or absorbent material that was peeled away by
the pressure sensitive tape during the test. This is called
Mass.sub.(peeled).
[0149] 10) Calculate the lamination efficiency of the specimen by:
8 Lamination Efficiency = Mass ( peeled ) Area ( peeled ) - BW
[0150] 11) The units of Lamination Efficiency are g/cm.sup.2.
EXAMPLES
[0151] The following numbered Examples describe materials, which
were made and tested in accordance with the test protocol herein to
generate the data are tabulated in Table 1.
[0152] Examples 1-9 will be resistant to cutting, and therefore
fragments are less easily freed from these materials during cutting
operations, and less likely to contaminate food items being
prepared. In particular, the cut-resistant surfaces (i.e., bonding
material surfaces) of examples 1-9 will have a lamination
efficiency of at least 10 g/m.sup.2 or pass as a result of
incomplete peel.
Example 1
[0153] A 34.2 g/m.sup.2 polypropylene scrim manufactured by Conwed
Plastics(g, Inc. having 25.59 strands per 10 cm in the machine
direction and 31.50 strands per 10 cm in the cross machine
direction was bonded to 100% SSK, 0.762 mm thick, 0.521 kg/m.sup.2
paper manufactured by Georgia Pacific.RTM., Inc. were used. The
scrim and paper were placed in a platen press and subjected 2296
kPa pressure at 177.degree. C. for 75 seconds.
Example 2
[0154] A 48.9 g/m.sup.2 polypropylene scrim manufactured by Conwed
Plastics.RTM., Inc. having 20.51 strands per 10 cm in the machine
direction and 23.62 strands per 10 cm in the cross machine
direction was bonded to 100% SSK, 0.762 mm thick, 0.521 kg/m.sup.2
paper manufactured by Georgia Pacific.RTM., Inc. were used. The
scrim and paper were placed in a platen press and subjected 2296
kPa pressure at 177.degree. C. for 90 seconds.
Example 3
[0155] A 15 g/m.sup.2 polypropylene carded nonwoven manufactured by
The Stearns Technical Textiles Co..RTM., having a 9 denier fiber,
was bonded to 100% SSK, 0.762 mm thick, 0.521 kg/m.sup.2 paper
manufactured by Georgia Pacific(t, Inc. were used. The scrim and
paper were placed in a platen press and subjected 2296 kPa pressure
at 177.degree. C. for 90 seconds.
Example 4
[0156] A 34.2 g/m.sup.2 polypropylene scrim manufactured by Conwed
Plastics.RTM., Inc. having 25.59 strands per 10 cm in the machine
direction and 31.50 strands per 10 cm in the cross direction was
bonded to 100% SSK, 0.635 mm thick, 0.456 kg/m.sup.2 paper
manufactured by The Herty Foundation.RTM., Inc.were used. The scrim
and paper were placed in a platen press and subjected 2296 kPa
pressure at 177.degree. C. for 75 seconds.
Example 5
[0157] A 48.9 g/m.sup.2 polypropylene scrim manufactured by Conwed
Plastics(g, Inc. having 20.51 strands per 10 cm in the machine
direction and 23.62 strands per 10 cm in the cross direction was
bonded to 100% SSK, 0.635 mm thick, 0.456 kg/m.sup.2 paper
manufactured by The Herty Foundationg, Inc. were used. The scrim
and paper were placed in a platen press and subjected 2296 kPa
pressure at 177.degree. C. for 90 seconds.
Example 6
[0158] A 15 g/m.sup.2 polypropylene carded nonwoven manufactured by
The Stearns Technical Textiles Co..RTM., having a 9 denier fiber,
was bonded to 100% SSK, 0.635 mm thick, 0.456 kg/m.sup.2 paper
manufactured by The Herty Foundation.RTM., Inc. were used. The
scrim and paper were placed in a platen press and subjected 2296
kPa pressure at 177.degree. C. for 90 seconds
Example 7
[0159] A 34.2 g/m.sup.2 polypropylene scrim manufactured by Conwed
Plastics.RTM., Inc. having 25.59 strands per 10 cm in the machine
direction and 31.50 strands per 10 cm in the cross machine
direction was bonded to 100% NSK, 0.559 mm thick, 0.406 kg/m.sup.2
paper manufactured by The Smurfit Stone Container Corporation.RTM.
were used. The scrim and paper were placed in a platen press and
subjected 2296 kPa pressure at 177.degree. C. for 75 seconds.
Example 8
[0160] A 48.9 g/m.sup.2 polypropylene scrim manufactured by Conwed
Plastics.RTM.t, Inc. having 20.51 strands per 10 cm in the machine
direction and 23.62 strands per 10 cm in the cross machine
direction was bonded to 100% NSK, 0.559 mm thick, 0.406 kg/m.sup.2
paper manufactured by The Smurfit Stone Container Corporation.RTM.
were used. The scrim and paper were placed in a platen press and
subjected 2296 kPa pressure at 177.degree. C. for 90 seconds
Example 9
[0161] A 15 g/m.sup.2 polypropylene carded nonwoven manufactured by
The Steams Technical Textiles Co..RTM., having a 9 denier fiber,
was bonded to 100% NSK, 0.559 mm thick, 0.406 kg/m.sup.2 paper
manufactured by The Smurfit Stone Conainer Corporation.RTM. were
used. The scrim and paper were placed in a platen press and
subjected 2296 kPa pressure at 177.degree. C. for 90 seconds.
2TABLE 1 Tabulation of Paper, Absorbent Efficiency, Cut-resistance,
and Lamination Efficiency for Examples 1-9. Absorbent Lamination
Efficiency Cut-resistance Efficiency Paper g.sup.2/(cm.sup.5sec)
(kgf/cm) (grams/meter.sup.2) Example 1 3.7 63.1 Pass* Example 2 4.5
53.4 Pass* Example 3 3.7 59.9 Pass* Example 4 1.9 58.3 375.8
Example 5 2.4 49.7 Pass* Example 6 1.4 59.5 Pass* Example 7 1.7
62.0 118.9 Example 8 1.6 56.9 145.4 Example 9 0.8 76.2 Pass*
*Incomplete peel indicating well integrated bonding and absorbent
layers.
[0162] The foregoing examples and descriptions of the preferred
embodiments of the invention have been presented for purposes of
illustration and description only. They are not intended to be
exhaustive or to limit the invention to the precise forms
disclosed, and modifications and variations are possible and
contemplated in light of the above teachings. While a number of
preferred and alternate embodiments, systems, configurations,
methods, and potential applications have been described, it should
be understood that many variations and alternatives could be
utilized without departing from the scope of the invention.
[0163] Thus, it should be understood that the embodiments and
examples have been chosen and described in order to best illustrate
the principals of the invention and its practical applications to
thereby enable one of ordinary skill in the art to best utilize the
invention in various embodiments and with various modifications as
are suited for particular uses contemplated. Accordingly, it is
intended that such modifications fall within the scope of the
invention as defined by the claims appended hereto.
* * * * *